Means and method of making metal strip



MEANS AND METHOD OF MAKING METAL STRIP Filed Sept. 25, 1950 '7 Sheets-Sheet 1 fig. IA

l N V E N T O R A ore/72 /1/e/se /7 M214, Mi

Dec. 22, 1953 IVERSEN MEANS AND METHOD OF MAKING METAL STRIP 7 Sheets-Sheet 2 Filed Sept. 23, 1950 Ill lllllll INVENTOR ore/72 /1/e/1s"e=/7 l p l h:

Dec. 22, 1953 IVERSEN 2,563,784

MEANS AND METHOD OF MAKING METAL STRIP Filed Sept. 25, 1950 '7 Sheets-Sheet I5 l/ /77 A W /7 ///A INVENTOR A ore/72 Weave/7 Dec. 22, 1953 WERSEN MEANS AND METHOD OF MAKING METAL STRIP '7 Sheets-Sheet 4 Filed Sept. 25, 1950 Qmm QWW

alkanllllll INVENTOR lore/72 /1 e/"s/7 5 Dec. 22, 1953 L. IVERSEN MEANS AND METHOD OF MAKING METAL STRIP '7 Sheets-Sheet 5 Filed Sept. 23, 1950 NN\\\\\ ms INVE NTO R A ore/72 Wensen a; A 6' W 4744.4

Dec. 22, 1953 Filed Sept. 23. 1950 L. IVERSEN MEANS AND METHOD OF MAKING METAL, STRIP 7 Sheets-Sheet 6 lNVE OR Lore/72 Ave/sen Dec. 22, [V R EN MEANS AND METHOD OF MAKING METAL STRIP 7 Sheets-Sheet '7 Filed Sept. 25, 1950 l N V E N T O R Z ore/72 08m? strip. While an unbroken section of continuous strip is moving through theillustrated mechanism the idler rollers II, It and 30' turn freely, the pinch rolls [4, I5, 26 and 2? drive, and the clamps 2!! and 2! are diseng'agedso thatthe strip moves through the mechanism=along a normal pass-line indicated generally at 3|, extending between the carrier bars I3 andgZjdgpdgbetween the upper and lower elements of the clamps 2i; and 2 l. The units of the apparatus Iii are carried ona base 32 comprising a pair of longitudinal beams 33,: and 34;. and a pair of'cross beams tii and 35 secured; between the beams33 and 34 (Figures 2A, 2B andVB). Theidler rollers H and 3e are journaled-in fixed relationto the base 32, and theI'stri-p edgeguides l2; and. 29 are likewise mounted on stands secured to the base 32. The guides l2 and 29.eachvcomprise vertical guiding elements 7, 31; and 38: movable,- toward v and from each other by oppositelythreaded screw elements 39=i=and diljournaled .infixed supports and rotatablelbyhand wheels d! to. adjust the edge guiding elements forvariousiwidths of strip, as illustrated in Figuredionthe guide 1 2.

The pinchroll housings l6 and Marc mounted onthe base 32 for movementparallelto the passline'3l through the apparatus iii. As shown in Figure 4, the pinch rolls and l5are generally irr the form of cylinders rolling substantially tangentially together at the pass-line with grooves 42 in the rolls to receive the carrier bars in. The lowerroll -l5. isjour-naled in fixed supports in the housing It and has an integral neck G3 mounting a :,worm-wheel;;44 'bywhich the roll it is driven by ya ;mQtOl',44- (Figure elA) through a worm it (Figure 4). The upper roll i lis driven from the shartzof; roll lfigthrough spur gears a and 45b. The upper roller I4 is journaled in bearing boxes 46 mounted for vertical sliding movement in the housing l6 ;and urged downwardlyby springs il extendingbetween upper spring, caps c8 adjustable inithehpusing lfi bymeans of boltsds, and lower spring caps 48a secured to the bearing boxes ill-i by-rodsgfitbh The caps 48a act as pistons in enclosedspaces therebelow which are connectedthrou hkports 480 with asource of compr essed-air iorreleasably lifting the caps 43a and roll M. The weight of the housing I6 is carried by;,double-fianged- -rollers Ellrolling on tracks 5i secured-to and extendingalong thelongitudinal base beams 33,,and 34. The motor id is secured to an extension of the-frame of the housing 56 and; moves withthehousing l6 valong the beams 33 and -34, on the.-rollers 50 The housing28 is constructed in the same way as the housing IE and rolls onextensions. of thesametracks 5i on the beams 33 and. y The pinch rolls 2t and 2'! are-drivenbya motor ;52 mounted on and carried with the housing 28. The motors 44 and 52 are (Figure 4), and extending slidably through a similar lower extension 55 of the roll housing 28. An integral flange 56 on the tie rod 53 adjacent an abutment 51? on the extension 55 serves to limit movement or the housings l6 and 28 toward each other. The tie rod 53 projects through the extension 55 anda cupbs is slidably mounted thereon between the extension and a pair of lock nuts 59 and 68 secured to the end of the rod 53. A compression spring 6! between the base of the cup 58 and the nut 5d urges the cup 58 against the extension 55 and thereby acts on the tie rod 53 to urge the housing It toward the housing 23 until the tie rod'fiange 55 engages the abutment 57 of theiho'using 23.-

A plunger 62 is secured at one end to the lower extension-5d of the roll housing [6 and projects at its other end into an actuating cylinder 63 in a stationary mounting Ed on the base 32. When the roll housing it moves toward the shearing stand I?! the'plung'er t2v retracts inthe cylinder 53 until a spacer 5511s engaged between anabutment 35a on the moving lower housing extension:

E i and the stationary projecting end of thevcyle inder 63.

63, so that the spacer 35 is supported to extend shearing stand ii is illustrated by the dotted circles l4 and i5 showing the extreme position or" the pinch rolls it and l 5 adjacent the shearingstand H.

A plunger El is secured at one end to the lower extension or" the roll housing 28 and at its other end extends into an actuating cylinder 63 in the fixed mounting 5d. The cylinder 68 has fluid inlet and outlet conduits connected to its extreme inner end and when fluid under pressure is supplied to the cylinder 68 to actuate" the plunger 5 the roll housing 28 is therebymoved in a direction away from the shearing stand ll until an abutment 53 on the lower extension 55 or" the housin engages a fixed stop it secured to the base 52. When this occurs the pinch rolls 25 and 2? are in the position shown in dotted lines at 25' and 2?. When fluid under pressureis supplied to-the cylinder 53 to actuate the plunger 62 so that the rolihousing, i6, tie rod 53 androll housing 28 are drawn back toward the entry idler roller ii, the roll housing 23 continues to move in this direction until a spacer H is pressed between the projectin end or" the cylinder 68 and an opposite abutting face of the lower extension 55 of the roll housing 28. The spacer ii is in the form of an inverted U secured to a lift ring '72 and is removably supported on the end of the cylinder 88 (Figure 26) in the same manner as describedabove. After the return movement of the roll housingi'e is stopped by the spacer H the continued movement or" the roll housing 16 in the same direction is opposed only by the resilient action of the springs! until the nut159 engages the adjacent end of the cup 53 and thereby locks the tie rod 53 and hence the roll housing is to the roll housing 23 so that further movement; of

the roll housing is in the direction of the entry idler roll ii is halted. The amount of this over run of the roll housing is is preferably in the,

order of /4 inch and is provided by spacing the nut 59 by such a distance from the end of the cup .1 58 when. the tie rod flange 56 and the base of the' The spacer. 65 is in the form or" an.v inverted U secured to' a lift ring 6%. having a. dependent projection adapted to fitinto a recess. in the top of the projecting end of theicylinderi cup 58 are both in engagement with the lower extension 59 of the roller housing 28.

The plungers 62 and 61 each have a conduit connected to a suitable source of compressed fluid (not shown). A common switch valve is preferably connected to the two conduits so that when fluid is supplied to one of the cylinders the other is permitted to exhaust, and so that when the valve is in neutral position the conduits of both cylinders are locked against escape of fiuid therefrom. In this way the plunger 62 is locked in full extended position against the action of the spring 9I with the nut 59 engaging the cup 58 when the roll housing I 9 is returned to its ready position nearest the delivery idler roller II (in the position shown in full lines in Figure 2A). The shearing stand I"! has a pair of horizontal cutting blades '13 and 74 adapted to cut a strip or a pair of overlapping strip ends at right angles to their line of travel and across their widths. The upper blade 13 is actuated by a pair of rams 75 (Figure 1A) against the action of a pair of springs 26 for returning the blade 13 to its raised position. A pair of spring-pressed holddown rods 7? are mounted on the frame which Supports the upper blade 13 and move up and down with the blade 13 in order to hold the strips beneath the blade during the cutting operation. The lower blade 14 is secured in a fixed frame having a flat upper surface level with the upper edge of the blade 14 and adapted to cooperate with the hold-down rods 71 during the cutting operation. A spring-mounted stripper 78 extends along the side of the blade 14 beneath the upper blade I3 and is restrained against movement above the level of the blade 14. When the upper blade 73 moves down during the cutting operation the stripper I8 yields resiliently. When a pair of strips are cut the incoming leading end is preferably placed over the outgoing trailing end so that the severed portion of the trailing end can fall down along an inclined face 59 of the stripper 18 into a suitable trough 19a. The severed end of the incoming leading strip end is then removed by hand after the blade 13 and the hold-down rods TI have returned to their raised position. The lower blade 14 and stripper it are positioned substantially below the pass-line 3i and the nearby supporting idler roller I8 is mounted tangential to the pass-line 3| in order to hold the trailing strip end higher than the following strip end after the shearing operation. This difference in level is important for causing the ends to overlap and not abut each other when the roll housing I6 is moved toward roll housing 23 preparatory to transferring the trimmed ends to the welder.

The clamps 29 and 2I mounted on the welding stand it comprise a pair of spaced lower clamping plates 82 and 88a fixed to the welding stand 19 and a pair of upper clamping plates 8| and 82 secured to beams 93 and 84. A pair of actuating units 95 and 86 each comprising a hydraulic ram and opposed spring are connected to the opposite ends of the beam 83 so that the springs bias the clamping plate 8| up and the rams move it down, and a like pair of actuating units 81 and 338 are connected to the opposite ends of the beam 9 for moving the clamping plate 82 up and down. The conduits of all of the rams of the units 85-88 are connected to a common source of fluid under pressure and discharge reservoir with a single control valve (not shown).

A welding head 22 (Figures 1A, 5 and 7) is mounted on the welding stand I9 for movement across the path of strip through the clamps 28 and 2| at right angles to the line of movement of the strip and exactly parallel to the blades 73 and I4 of the shearing stand I! (the vertical central plane of movement of the welding wheels 23 and 24 is indicated by the dotted line 22a in Figure 2A). A pair of bronze bearing strips 89 and 98 are secured to the frame I9 and slidably support the travelling base 9| of the welding head 22. A lower welding head frame 92 is bolted at 93 to the base 9| and is electrically insulated therefrom by insulation 94. An upper weld-- ing head frame 95 is bolted at 96 to the lower frame 92 and is electrically insulated therefrom by insulation 91. The upper welding wheel 23 is mounted on the upper frame 95, the lower welding wheel 24 is mounted on the lower frame 92, and a transformer 98 is mounted on the frames 92 and 95 with one of its poles electrically connected to the welding wheel 23 and the other pole electrically connected to the welding wheel 24 in order to pass a low voltage, high amperage welding current between the wheels 23 and 24 through the frames 92 and 95 and the connecting wheel mountings. Flexible cables 98a supply electric power to the transformer 98. A pin 99 (Figure 5) on the travelling base 9I engages spaced limit switches I88 and IN on the stationary frame I9 to turn the welding current on and then off as the rollers 23 and 24 begin and end their pass across a pair of overlapping strip ends. In order to cool the welding wheels, which are preferably of bronze, a flexible water supply line I82 is connected to flexible hoses I83 and I84 with nozzles I85 and I86 disposed adjacent the welding wheels 23 and 24 and directed to spray water toward the points of welding contact of the said wheels. The wheel 23 is carried between brackets I81 pivoted on a fixed stud I88 secured to the frame 95. The brackets I81 have a rear extension I89 connected through a link H8 with a lever III pivoted on a stud H2 extending from the frame A counterweight i I3 is mounted on the opposite end of the lever III and is adjustable therealong to vary the downward pressure applied to the welding Whee1 23 by the counterweight H3 through the connecting linkage just described. Downward movement of the welding wheel 23 is limited by an adjusting screw I I4 threaded in the frame 95 and abutting the end of the lever III connected to the link H8. The welding wheel 24 is similarly carried between a pair of brackets H5 pivoted on a stud H6 projecting from the frame 92. A rear extension I i! of the brackets H5 is connected through a link H8 to one end of a lever H9 pivoted on a stud I28 projecting from the frame 92. The other end of the lever H9 abuts an adjusting screw I2I threaded in the frame 92. The screw I2! acts through the linkage just described to support the welding wheel 24 and to adjust its vertical position.

The welding wheels 23 and 24 are moved across the width of the strip ends to be welded (see full line and dotted line positions of the welding Wheels in Figure 6) by a double-acting hydraulic unit comprising a fixed ram I22 having one end secured to the stationary base I9 and its other end mounting a double-acting piston I23, and a cylinder I24 integral with the travelling base BI and slidably enclosing the piston I23. Both ends of the cylinder I24 are closed, one of them being in sliding sealed engagement with the ram I22, and the spaces in the cylinder I24 on opposite sides of the piston I22 are alternately supplied escapes with actuating fifiidun'd resort tl ioiigh='siiit= able conduits opening tli to and estefidmg through the interior of the" r In [22 eras-r to shiftthecylinder ma (1- hence the'welding head 22- back and-for'thtof "essive welding operations. The wldin' opera on is illustrated in Figure 9; whereas pair of ov rlapped strip'eii'els l25 (leading) and I26 (trailing) are sho'wn iri section before bei'ng' welded; and Figure 10; where the same sectioned portions of the st-rip ends W and I26 are shown being fused together between the weldingwheeis zr and 24;

The preferred opera n of the wholeappai'atus H is outlinedas follows:

When the i'irailing one ofa metal strip passin through the apparatus reash'es' the entry carrier bar's I3 the pinch rolls M;- l 5-', 26 and 2? are slowed down and-the delivery pinch" rolls 2E and 2-1? are stopped and thereby" locked against rota: tion just before the said trailing and passes be tween the shearing blades 13 and I4; The-lead ing end of another new strip is then drawn over the entry idler roller H and is passed between the entry carrier bars i3 and the entry pinch rolls M1 and L5 which-are then-operatedto advance the leading end just beyond the shearing blades; i3 and T l. The leading? end automatically slides; over the trailingstrip" end between the shearing blades; entry pinch roll's Mr and is are then stopped? and thereby locked against rotation, andthe rains I? are actuated to cause the: shearing blade 13 to move down and shear the pair of overlapping st-rip' ends positioned be-' low it: The severed end of the trailing strip end drops downwardly fromthe sloping face" of the stripper l9 and the severed end of the" leading strip end is: removed: manually.- The trimmed ends are parallel each other as a result of being outtogether and the trimmed trailing end is held: by the idler l8 slightly above the other trimmed: trailing end resting on the stripper it; During these operations both of the pinch roll housings t6: and 2-8 are in their extreme positions toward-the entry end ot theapparatus H} (shown in full lines: Figures 2A and 2B) The fluid locked. in the cylinder 63' is then released so that thespringa 61 movest-he tie rod 5-3- until its flange 5a"; engagesthe abutment: 5 1- of-- the lower exten-- sion 55 of the pinch roll housing 28; thereby moving the: pinohroli housing H3 a small; pre-' determined distance preferably in the order oifl of aninch, towardrthe shearingstand i i. This causes the trimmedleading. strip end tounclei lap the trailing trimmed strip end by A of an inch-in the shearing'standilfl ,and-fluid isthefi (or simultaneously) supplied-under pressure to the; ray-lin oer 68 to move the roll: housing 2-3 with the leading strip end locked between; the pinch rolls 26 andZE-unt'il the fixed stop l0 stops this movement; Iii thefne'anwhile the compression spring" 61., whicli'ha's initially eXpanded to cause the described inch overlap of the strip ends in the shearing stand IT, acts" throng-H the tie rod 53" to draw the pinch r'o'll housing 16' with the pinch r'oll" ho'u'singfzli so that" the A. inch overlap emana es-(1" while" the 0verlapping strip ends" pass from the shearing stand IT through the welding clamps' 2t? 'ifhepincnrou li'ous t6 ishaltedby thespacer't'i and the-compression spring or deflects to permit' the" slight additional movement of thefpincli'rollfhousihg 231'intil it is halted bythe fi'xed stop iii; The fluid iii-the cylinder 68" is locked w "e'n the'pinchjroll housing 28 reaches" the stop T in order't'd'halt it there against the." actioriid h e{ spring 61 This n'io' e: menr of the their roll hoii'sifi g 2 3" after mcve:

new; or the pinch roll housing It has ceased reduces the-overlap between the strip ends by a predetermined amount calculated to leave the strip ends very slight Overlapping relation directly between the path of the contacting m faces of the Welding wheels 23 and 24 (Figure 9). For example, when welding 2 1'-gauge low carbon steel strip an overlap of of an inchgives very satisfactory results with Welding wheels having 4 inch tread travelling at a rate or" 35 feet per minute'with a pressure of '800 pounds between the wheels and using a welding current of 14,000 amps. at 13.3 volts.

After the pinch roll housings l6 and 28 have completed their movement to position the strip ends in the desired overlapping relationship for welding the rains 88 are operated to close thewelding clamps- 2li' and 2! to secure the strip en'dsin the slightly overlapping relation deter mined by the positions of the'pin'ch roll housings l6 and 28, and the ramcylinder I22 is then sup plied with fluid under pressure at one end or the other; depending upon the position of the welding head 2-2- atthe beginning of the welding operation, to draw the welding wheels 23 and 2'4 across the clamped overlapping strip ends. As soon as the welding wheels first contact the strip ends the welding current is turned on and kept on continuously while the welding: wheels move across the full width of the overlapping strips to complete the welded joint. During this weldingoperation water is supplied through the nozzles Hi5 and its to coolthe welding wheels and thereby prevent themfrom' reaching temperatures which would injure their welding surfaces. A predetermined pressure between the welding wheels is maintained during the welding opera tion by the counterweight i3. Buring' the weld ingoperation the current between the welding wheels heats the overlapping strip ends until they fuse and at the same time the pressure between the wheels plus the greater width of the wheels than the amount of overlap of the strip ends causesthe wheels to roll and mash down the momentarily soft fused metal at each portionof the joint so that the completed joint is ofsub stantial-ly the sam thickness and surface smoothnessas the unwelded s rip portions on each side thereof (Figure 10 The strip ends ores narily have some variation of cross-sectional thickness transversely across the strip; and the welding wheels are able to follow the resultant ca inbered pro file of the overlapped strip ends while maintaining a constantpressure through the action of the pivotal, weightedmounting of the weldingwheels. As a result: there isno need for any subsequent d ning or grinding operation along the welded joint to prevent injury to prtessnig equipment siibseqtenuy receiving the con 'udus strip formed from the two welded s'tri'ps.

Ait the conclusion-of the weldingoperation the welding head 22- is left in the' positiofiwhich-it has reaoliedwith the weldingc'urrent turned off aiidthe matt traversing cylin er 22' locked the'l cylinderto new the welding" new stationary; ressure in the" damping" rains 85 8315 released and the weldingeiamps 201 and 21' spring open; ressure in the cylinder 691s" released so that the pine-i; roll Housing 281s drawn tOWldI housing it awa from fixed stop 10 V as spring 6 l expands until the tie rod collar 56 engages the abutment; 5T. TH6 cylih d el' 63 isthen supplied with fluid' under pressure to more" the pinch roll U Hous ngs it" and 2'2" bacjki'to their miter positio until" return movement" of liaising" 28 stiifipt d' by the spacer ll engaging the lower extension 55 of the pinch roll housing 28. Additional fluid is supplied to cylinder E3 to continue the return movement of housing it against the action of spring ill until nut 59 engages cup 53. During the return movement of the housings l5 and 28 all of the pinch rolls l d, 15, 26 and 2? are pre ferably separated to prevent pulling the continuous strip toward the delivery end or the apparatus Ill. After completion of the return movement of housing it the fluid in the cylinder 63 is locked therein to hold the roll housings l5 and in position for the next operation, and regular movement of strip through the apparatus if) is resumed until another section of strip is to be added.

While I have illustrated and described a present preferred embodiment of the invention and certain present preferred methods of practicing the same it will be recognized that the invention is not limited thereto but may be otherwise variously embodied within the scope of the following claims.

I claim:

1. The method of making a continuous length of steel strip from a plurality of end-to-end strips comprising the steps of trimming the ends of a of steel overlapping the trimmed ends by not more than one thirty-second of an inch, clamping the strip ends close to and on both sides of the whole length of the overlap, and passing welding current through the overlapped ends progressively across the width of the clamped strips while simultaneously rolling down the welded joint as it fuses flush with the adjace'nt unwelded strip ends.

The method of making a continuous length of steel strip from a plurality of end-to-end strips comprising the steps of trimming the ends of a pair of steel strips, overlapping the trimmed ends between one thirty-second and one sixty-fourth of an inch, clamping the strip ends close to and on both sides of the whole length of the overlap, and passing welding current through the overlapped ends progressively across the width of the clamped strips while simultaneously rolling down the welded joint as it fuses flush with the adjacent unwelded strip ends.

3. The method of making a continuous length of steel strip from a plurality of end-to-end strips at least some of which vary in thickness transversely across the strip, comprising the steps of trimming the ends of a pair of steel strips, overlapping the trimmed ends between one thirty-second and one sixty-fourth of an inch, clamping the strip ends close to and on both sides of the whole length of the overlap, and passing welding current through the overlapped ends progressively across the width of the clamped strips while simultaneously yieldably applying a constant pressure and rolling down each portion of the welded joint as it fuses flush with the adjacent unwelded portions of the strip ends, whereby each portion of the overlapped strip ends is welded substantially flush with the adjacent unwelded portions of the strips regardless of variation of thickness of the overlapped strip ends transversely across the strips.

4. The method of making a continuous length of steel strip" from a plurality of end-to-end strips, comprising the steps of overlapping the adjacent ends of a pair of steel strips arranged end to end and shearing said overlapping ends simultaneously, removing the trimmings, moving the trimmedends vertically relative to each other into different horizontal planes and then horizontally toward each other into an initial predetermined overlapping relation not exceeding one thirty-second of an inch, and thereafter moving the strips laterally with the trimmed ends in said initial overlapping relation until the leading end of the trailing strip reaches its position for welding and then stopping the trailing strip and continuing the lateral movement of the lead ing strip until its trailing end has reached its welding position, the difference in travel of the strips after the initial overlap being less than the initial overlap so that the final overlap of the trimmed ends in welding position is reduced to a small predetermined amount of overlap, clamping the strip ends adjacent and along both sides of the reduced overlap, and while clamped progressively pressure-rolling and simultaneously passing welding current through the overlapped ends across the width of the strips to form a welded joint flush with the adjacent unwelded strip ends.

5. Apparatus for making a continuous length of metal strip from a plurality of end-to-end strips, comprising a shearing unit for trimming strip ends, a strip welding unit comprising a pair of welding wheels on a carriage with means pressing the wheels together as they are moved by the carriage along a pair of slightly overlapping strip ends to mash-weld them together, a pair of elements adapted to clamp strips and disposed with the shearing and welding units in line therebetween, said elements being mounted for lateral movement in the direction of said line for moving trimmed strip ends from the shearing unit to the welding unit, means between the shearing and welding units 'for supporting the trimmed strip ends during such movement, power means connected to one of said elements to move it in one direction, power means connected to one of said elements to move it in the opposite direction, a connection including a resilient link between said elements, stop means differentially limiting lateral movement of said elements in the direction from the welding unit to the shearing unit so that the element nearest the welding unit is stopped first and the other element travels a predetermined greater distance against the action of said resilient link, and stop means differentially limiting opposite lateral movement of said elements so that the element nearest the shearing unit is stopped first and the other element travels a predetermined greater distance which is less than the first-mentioned greater distance, whereby after the elements are first moved against the first-mentioned stop means and are then clamped on a pair of trimmed ends in the shearing unit, the resilient link automatically causes an initial overlap of the trimmed ends before lateral movement of both ends to the welding unit begins, and the second-mentioned stops automatically reduce the overlap to a predetermined small amount when the trimmed ends reach the welding unit.

6. Apparatus for making a continuous length.

strip ends during such movement, power means connected-to one of-said elements to move it in one direction, power means connected toone of said elements to move. it in the opposite direction, a connection including a resilient link between said elements, stop means differentially limiting lateral movement of said elements in the direction from the welding unit to the shearing unit so that the element nearest the welding unit is stopped first and theother element travels a predetermined grater distance against the action of said resilient link, and stop means differentially limiting opposite lateral movement of said elements so that the element nearest the shearing unit is stopped first and the other element travels a predetermined greater distance which is less than the first-mentioned reater distance, whereby after the elments ar first moved against the first-mentioned stop means and are then clamped on a pair of trimmed ends in the shearing unit, the resilient link automatically causes an initial overlap of the trimmed ends before lateral movement of both ends to the welding unit begins, and the second-mentioned stops automatically reduce the overlap to a predetermined small amount when the trimmed ends reach the welding unit.

'7. Apparatus according to claim 6 wherein the shearing unit comprises cutters for simultaneously trimming two overlapping strip ends, and supports for the respective ends at difierent levels on opposite sides of the cutters, thereby positioning the trimmed ends to be overlapped in the shearing unit before being moved to the welding unit.

8. Apparatus for making a continuous length of metal strip from a plurality of end-to-end strips, comprising two pairs of pinch rolls, a shearing unit and a welding unit spaced therefrom along the pass line between the two pairs of rolls, rotary braking means and independent rotary driving means for each pair of rolls, a.

housing each p il 91 1 laterally mov ble along the pass line through the two pairs of rolls, whereby the rolls are rotatable to position the adjacent ends of two strips in end-to-end relation for trimming in the shearing unit, and are laterally movable while locked against rotation to position the trimmed ends in the welding unit, and means to separate each pair of rolls so that the welded strip is undisturbed While the roll housings are moved laterally back to their initial position.

9. Apparatus for making a continuous length of metal strip from a plurality of end-to-end strips, comprising two pairs of. pinch rolls, a shearing unit and a welding unit spaced therefrom along the pass line between the two pairs of rolls, rotary braking means and independent rotary driving means for each pair of rolls, a housing for each pair of rolls laterally movable along the pass line through the two Pairs of rolls, whereby the rolls are rotatable to position the adjacent ends of two strips in end-to-end relation for trimming in the shearing unit, and are 'laterally movable while locked against rotation to position the trimmed ends in the welding unit, stops limiting movement of the respective housings in both directions along the pass line, said stops causing relative movement of the housings at the end of the travel of the housings in both directions in order to impart a predetermined overlap to trimmed strip ends positioned in the welding unit, and means to separate each pair of rolls during at least the final portion of the return movement of the housings so that relative movement of the housings'at end. of their return movement will not disturb the welded strip.

10. Apparatus for making a continuous length of metal strip from a plurality of end-to-end strips at least some of which vary in thickness transversely across the strip, comprising means to hold a pair of such strip ends in slightly overlapping relation, a pair of welding wheels sub-- stantially wider than the overlap of the strip ends whereby to project over the cooler portion of the strip on each side of the overlap, an electric circuit connected to the welding wheels to pass welding current therebetween, a carriage movable transversely of the strips parallel to the transverse edges of their overlapped ends and mounting the wheels for movement relative to each other and for rolling along opposite sides of said overlapped strip ends, and means yieldably biasing the wheels together with force sufficient to mash down the successive portions of the overlapped ends being fused by the welding current whereby the welding wheels follow the contour of the overlapped strip ends to make a substantially smooth flush weld at each portion of the overlapped ends regardless of variation of thickness of the strip ends transversely across the strips.

11. Apparatus for making a continuous length of metal strip from a plurality of end-to-end strips at least some of which vary in thickness transversely across the strip, comprising means to move a pair of such strip ends. into position to be welded in slightly overlapping relation, clamps engageable across each strip closely adjacent the overlapping ends, a pair of welding wheels substantially wider than the overlap of the strip ends whereby to project over the cooler portion of the strip on each side of the overlap, an electric circuit. connected to the welding wheels to pass welding current therebetween, a carriage movable transversely of the. strips parallel to the transverse edges of their overlapped ends and mounting the wheels tor movement relative to eachother for rolling along opposits sides of s id o rlapp d st ip d means yieldably biasing the Wheels together with force sufiicient to mash down the successive portions of the overlapped ends being fused by the welding current whereby the welding wheels follow the contour of the overlapped strip ends to make a substantially smooth flush weld at each p tion o the overl ppe ends ardl ss f variation of thickness of the strip ends transversely across the strips.

12. Apparatus according to claim ll in which the welding wheels each have a contacting tread width of about one-quarter inch, and the force applied to the wheels by the biasing means is about 800 pounds,

13. Apparatus for making a continuous length of metal strip from a plurality of endJo-end strips at least some of which in thickness transversely across the strip, comprisin means to hold a pair of such strip ends slightly over.- lapping relation, a pair of welding wheels substantially wider than the overlap of the strip ends whereby to project over the cooler portion of the strip on each side of the ove lap an lectr ircuit connected to the welding wheels to pass Welding current therehetween, a carr e me able transversely of the strips parallel to the transverse edgesof their overlapp d ends means on the carriage mounting the wheels for relative movement of their axes to vary their spacing and for m ne l ne Q n s t sides Qf sa doverlapn portions, adjustable means rigidly limiting the minimum spacing of the wheels, and a weight yieldably biasing the wheels together with force sufficient to mash down the successive portions of the overlapped ends being fused by the welding current whereby the welding wheels follow the contour of the overlapped strip ends to make a substantially smooth flush weld at each portion of the overlapped ends regardless of variation of thickness of the strip ends transversely across the strips.

14. Apparatus for making a continuous length of metal strip from a plurality of end-to-end strips movable in a fixed pass line through the apparatus, comprising a pair of pinch rolls, a shearing unit, a welding unit and a second pair of pinch rolls spaced from, each other along the pass line in said order, rotary braking means. and independent rotary driving means and a housing for each of said pair of pinch rolls, means mounting each said housing for movement along the pass line relative to the shear and welding units, means controlling the spacing between said housings during their said movement along the pass line, and means operable to shift said housings along the pass line, whereby the pinch rolls are rotatable to move the trail- References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,226,639 Cary May 22, 1917 1,230,114 Cary June 19, 1917 1,276,030 Gary Aug. 20, 1918 1,511,849 Taylor Oct. 14, 1924 1,865,530 Lutz July 5, 1932 1,936,314 Sykes Nov. 21, 1933 2,016,380 Lutz Oct. 8, 1935 2,024,597 Pfeiffer Dec. 17, 1935 2,078,365 Biggert Apr. 27, 1937 2,203,151 Iverson June 4, 1940 2,343,687 Martindell Mar. 7, 1944 2,362,388 MacChesney Nov. 7, 1944 2,369,830 Johnson Feb. 20, 1945 2,412,648 Rendell Dec. 17, 1946 

